Temp measurement not working

[oh2xx]

Hi,

I just installed two Dallas 18B20 but the temperature reading says -0.0625 for both units? Using FW 1.21 here. Any ideas?

73 de Kari, OH2XX

[ON4AOI]

looks like a bad connection to me Kari
check if the pins are correct connected

or maybe not at the correct pins

Guy ON4AOI

[Jan (Microbit)]

Hi,

I just installed two Dallas 18B20 but the temperature reading says -0.0625 for both units? Using FW 1.21 here. Any ideas?

73 de Kari, OH2XX

Was it the first sensors you have ever installed to that Webswitch? Did you install one per bus(A/B)? If there never has been installed sensors before then if the Webswitch is capable of finding them I would think it also would be able to get the temperature from them.

[oh2xx]

Yes, those were the first sensors I have ever installed to that Webswitch. And I did install one per bus(A/B).

I bought two more sensors today from another electronics shop just to make sure that there is nothing wrong with the components. The installation is so straight forward that I can not imagine having any problems there. Will test again later today...

[Jan (Microbit)]

Remember that if you either add the new ones or replace the current ones you will have to either delete the current ones from the 1-wire page or scan for new devices. That is because they all have unique IDs.

[oh2xx]

Now it is working. Never scanned for 1-wire devices so do not know if that was originally the problem. Now I have changed the sensors and scanned for new devices and it is all ok. Thanks for your support.

73 de Kari, OH2XX

P.S.
I am getting ready to run as OH2HQ remotely in the IARU HF contest on 80m CW. It will be a good test to see the performance of the remote setup. Have my home station for backup if needed though.

[Jan (Microbit)]

Great!

The way it is supposed to work is that if you install one sensor or two sensors(one per bus) on a Webswitch which never has had any sensor installed is that it automatically scans and saves that/those sensor(s). Doing so is for compability reasons with the heat and cold control functions being present in both the extended and non-extended version which did so. Adding more than one sensor per bus will need a manual scan though.

In your case it would have been valuable to know if there somehow were scanned 1-wire devices before you installed sensors for the first time. It should not have been the case, but if it was then it explains why you got no temperature values at first.